Tottenham boss Jose Mourinho criticised Michael Oliver for his decision to give Arsenal a second-half spot kick that saw Alexandre Lacazette slot home the winner in the north London derby.
Spurs took the lead despite a below-par display in the first period, Erik Lamela producing an impudent rabona in the box to beat Bernd Leno after Emile Smith Rowe had hit the bar earlier in the contest.
Cedric Soares then saw a strike crash off Hugo Lloris' left-hand post before Martin Odegaard's deflected effort off Toby Alderweireld left the tie fascinatingly poised going into the break.